This is a mod port of a datapack Ive made a while ago, I will probably be using the old page to create a non-mod version sometime in the distant future!

Biomes

Cold Forest

• Replace forests when they are close to a snowy region

Cold Plains

• Replace plains when they are close to a snowy region

Warm Forest

• Replace forests when they are close to a dry region
• This biome in the old datapack has Jungle trees mixed in, there are now Acacia trees instead

Warm Plains

• Replace plains when they are close to a dry region
• This biome in the old datapack has Jungle trees mixed in, there are now Acacia trees instead

Windswept Birch Forest

• Replaces Windswept Savannas in temperate regions, and is also in colder regions where Windswept Savannas failed to reach

Snowy Windswept Forest, Snowy Windswept Hills, and Snowy Windswept Gravelly Hills

• Nothing more than snowy variants of the vanilla hill biomes

Snowy Old Growth Spruce Taiga and Snowy Old Growth Pine Taiga

• Replaces taigas in snowy regions

Dark Grove

• A Dark Forest variant of the vanilla grove biome, generates in mountain slope areas around Dark Forests, Old Growth Taigas, and Snowy Old Growth Taigas

Snowy Cherry Grove

• A Snowy Slope Variant of Cherry Groves that appear on mountain slope regions in the frozen sections of the world (the areas with snowy plains)

Frozen Mangrove Swamp

• Where swamps would generate in snowy regions if given the opportunity

Warm River

• When a river cuts through a mesa or desert region

Red Desert

• A red sand variant of normal deserts, appears between Badlands biomes and the ocean

Red Warm River

• A red sand variant of the added warm river that appears whenever a river is in a Badlands or Red Desert

Red Warm Ocean

• A red sand variant of the Warm Ocean, appears where other red sand biomes generate
  Red Lukewarm Ocean

Deep Red Lukewarm Ocean

• Red sand variants of the vanilla Lukewarm Oceans, appears where Red Warm Oceans would, but in the hot regions

Red Beach, Snowy Red Beach

• replaces Beaches and Snowy Beaches in certain scenarios, these scenarios being the same as the Red Desert criteria
• due to this, I don't believe normal beaches will border Stony Shores

Snowy Stony Shore

• replaces stony shores in snowy regions

Mushroom Grove

• A thickly populated mushroom Island Variant

Eroded Mushroom Island

• An Eroded Variant to the Mushroom Grove
• appears in similar regions the Eroded Badlands Would

Cave Biomes

As it is with all worldgen additions, there are cave biomes

Mushroom Caves Otherwise known as Overdone Caves

• Appear under oceans when a mushroom Island is nearby (what its supposed to do at least)
• They have the same surface rules given to the mushroom biomes, but underground
• Are in here because someone wanted them

Frozen Caverns

• Ice Caves that appear under or near Snowy regions
• They have Ice and blue ice ores, packed and blue ice spikes (right-side-up and upside-down), and giant blue ice pillars similar to that of dripstone caves, just more... wavy?

Sand Caves

• Sandy caverns that should generate under or around deserts
• They house sand, husks, cactuses, dead bushes, sand, coarse dirt ores, glow lichen, sandstone floor and roof spikes, sand, sandstone cave pillars (like the ones in dripstone caves), warm ocean life in aquifers (corals, sea pickles, and tropical fish), and sand!

Red Sand Caves

• Red sandy caverns that should generate under or around deserts
• They house husks, cactuses, dead bushes, coarse dirt ores, glow lichen, red sandstone floor and roof spikes, red sandstone cave pillars (like the ones in dripstone caves), warm ocean life in aquifers (corals, sea pickles, and tropical fish), and red sand!

Gravel Caves

• Gravelly caverns that should generate under or around mountainous terrain
• They house cobblestone, cobbled deepslate, dead bushes, coarse dirt ores, glow lichen, cobblestone and cobbled deepslate floor and roof spikes, cobblestone and cobbled deepslate cave pillars (like the ones in dripstone caves), and gravel!

Structures (Requires Lithostitched)

There are two structures ported from the datapack

Swamp Villages

• Villages that spawn in Swamps

Mangrove Swamp Villages

• Villages that spawn in Mangrove Swamps and Frozen Mangrove Swamps
• A mangrove reskin of the swamp village